There is 6 values in MPU-6050 Accelerometer + Gyro. X, Y, Z in angle and X, Y, Z in acceleration.
I saw MPU-6050 Accelerometer + Gyro have FIFO Buffer, 1024 byte.
How many times does this size have the 6 values?
What size is one time value( X, Y, Z in angle and X, Y, Z in acceleration)?
60byte or What?
see this playground for some high level information.
Indeed, the MPU-60X0 contains a 1024-byte FIFO register that is accessible via the Serial Interface. As to your "How many times does this size have the 6 values?" question — the answer is "it depends on how your configure the device: There is a FIFO configuration register which determines which data is to be written into the FIFO."
You can get in there the gyro data, the accelerometer data, the temperature readings and also auxiliary sensor readings, + an FSYNC input. So really the number of bytes at each write depends. There is a FIFO counter which keeps track of how many bytes of data are in the FIFO and the interrupt function may be used to determine when new data is available.
The idea behind the fifo is that you can sleep your master device if it is fast instead of actively waiting for new sensor data to arrive. That helps with power hungry usage running on tiny batteries.
Thank you for your kind explanation.
I want to know how to read all values in register and delete them.
I'd like to real all values and transmit them to smartphone. and delete them.
If I do so, I can save battery power. because of one transmit instead of several transmit.
Is it possbbe?
Please do not PM me for help
What does PM means? I gues "do not ask privately". Is it correct?
Personnal message.
Indeed
What code are you using to request information from the fifo buffer?
Guessing but most use this library: i2cdevlib/Arduino/MPU6050 at master · jrowberg/i2cdevlib · GitHub
which has this file : MPU6050_6Axis_MotionApps20.h
that works with fifo buffer and calculates the angles for you within the MPU
and if that is the case 
which I could be wrong the answer is the update happens at every 10 milliseconds unless you change the following line located at line 305.
0x02, 0x16, 0x02, 0x00, 0x01 // D_0_22 inv_set_fifo_rate
// This very last 0x01 WAS a 0x09, which drops the FIFO rate down to 20 Hz. 0x07 is 25 Hz,
// 0x01 is 100Hz. Going faster than 100Hz (0x00=200Hz) tends to result in very noisy data.
// DMP output frequency is calculated easily using this equation: (200Hz / (1 + value))
// It is important to make sure the host processor can keep up with reading and processing
// the FIFO output at the desired rate. Handling FIFO overflow cleanly is also a good idea.